1 Destination address to where the packet is destined. Layer 3 protocols such an IP take care of this.
2 Neighboring routers from which remote networks can be learned of and packets can be moved to on way to its destination.
3 Routes to remote networks and a way to determine the best route to each of them.
4 Way to learn, verify and manage routing information. Incomplete, incorrect or unstable routing information is worse than not having any routing information. If a router does not have routing information, it will drop the packets and let the source know. If a router has incorrect routing information, loops can form and bring down networks.